First Look – Fatback Big Su 26″ Wheels

Back in the springtime at Sea Otter, muh man Fuzzy showed me Fatback’s new Big Su Aluminum Tubeless Ready Rim. The new rim weighs in at an ultra-svelte 640g. I’m not talking about ‘light for an alloy set of wheels’. I’m talking lighter than a bunch of the double wall carbon wheels on the market. Last April we compared 4 wheelsets that all have carbon rims. We weighed each set’s front wheel with a tire mounted tubeless and a 180mm brake rotor. Check out the updated chart below.

Wheelset (Rim/Hub/Tire) Front Weight (grams) Diameter (inches) Tire Width (mm)
Fatback Big Su81/Fatback/Schwalbe Jumbo Jim 26 x 4.0 2500 29.01 100
Reynolds80/Industry Nine/HuskerDu 26 x 4 2710 29.16 101
Pub75/DT Swiss/Terrene Cake Eater 27.5 x 4 2761 29.74 95
Borealis50/Borealis/Maxxis Minion FBF 27.5 x 3.8 2677 29.5 85
HED100/Onyx/Maxxis Colossus 26 x 4.8 3021 29.7 120
HED100/Onyx/Terrene Johnny 5 26 x 5.0 2930 30.2 123.43

The Aluminum Big Su is the lightest wheel on the list. Lighter than the carbon set of wheels that I’ve been riding all summer! Notice that I didn’t say the lightest in existence, because single wall carbon rims like the 85mm HED’s are about 190 grams lighter but compare the price of those wheelsets with the $699 MSRP of the Big Su’s. The Big Su’s are as light or lighter than the double wall carbon wheels (listed above) and cost a lot less.

Fatback has found a way to manufacture an 81mm wide alloy rim that only weighs only 640g and when laced up with their third generation Alaskan Series hubs with Jumbo Jims mounted tubeless creates a front wheel that only weighs 2500g. Readers at home please take the front wheel off of your fat-bike and weigh that sucker. Post your build specs and weights in the comments if you like.

Our set of Big Su’s came to us prepared for tubeless mounting to a set of Schwalbe Jumbo Jims. Fuzzy had suggested that we mount the tires ourselves, so we could experience how easily they would seat. Both tires snapped right into place on the first try. They mounted up dry using a compressor and after that, we added 4oz of sealant to each tire and we were in business. First time – full time -overnight and everything stayed air-tight and out’a-sight (70’s funk flashback)

Bandito Singletrack

The next morning, I took the new wheels out on my usual bandito loop. I wondered if I’d feel any let-down from the Summer 27.5 x 50mm wide wheels that I reviewed recently. Man…was I pleasantly surprised! The Big Su’s felt light and zippy. Light wheels get up to speed quickly and the low rolling resistance of the Jumbo Jims helped accentuate the feel of how quickly these wheels accelerate.

I’ve got a really nice long downhill on my home loop that transitions from asphalt to overgrown gravel two-track with puddles and some good sized potholes. My first run down that section on the big Su’s felt solid. Just as I hit warp speed, a large bird (I thought it was a hawk at first) swooped down out of one of the trees that line the left side of the doubletrack out in front of me. A moment later, when I shot past the tree, another half-dozen turkey vultures took flight from their perches overhead. As I thought to myself “How cool was that?” I rocketed down the road towards the railroad tracks and bunny hopped one of the big potholes. The landing felt and sounded rock solid.

I’ve gotten a couple of rides in before I left for Inter(E)Bike and so far I have no regrets or complaints about switching from 27.5 x 50mm to 26 x 81mm wheels. The Big Su – Jumbo Jim wheels are half an inch shorter than the 27.5 wheels that I had been testing but so far….that isn’t getting in the way of my super fun good times. I’ll be riding the Big Su’s during the shoulder season between now and early winter. Fatback also has a new Carbon Rim in the pipeline that’s rumored to shave a pound off of the Big Su’s, but that’s a story for the future! Look for a full review of the Fatback Big Su Wheels in about three fortnight’s time.

Felices Caminos Hombres!


One Response to First Look – Fatback Big Su 26″ Wheels

  1. Svein September 28, 2018 at 7:12 am #

    My complete front DT Swiss BR2250 with JJ4.0 Lite Skin and sram 180mm center lock rotor is 2359g. The Big Su is 35 grams lighter than DT Swiss BR710 rim, is the hub heavier or are you using a heavy rim strip?

    I’m using tyvek rim strip and one round of sunringle tubeless tape.

Leave a Reply